Witnesses said assailants opened fire on Constitution and
Federalism Minister Abdallah Deerow Isaq as he left prayers --
an attack sure to heighten tensions in the violence-plagued
Horn of Africa nation which many fear is sliding toward war.

"It looks like an organised assassination. ... We are very
sorry and are condemning this terrorist action," Information
Minister Mohamed Abdi Hayr told Reuters from Baidoa.

"They shot him as he was leaving the mosque then ran off."

A Baidoa hospital nurse said Isaq, a former schoolteacher,
came in with four bullet wounds in the heart and chest.

After the attack, the government blocked roads out of the
town, and about 1,000 protesters furious at the killing took to
the streets with sticks, knives and stones, witnesses said.
Scores of shops were looted in several hours of chaos.

"Bring out the killers!" protesters chanted outside a
police station, where officials said two captured suspects were
held.

Formed in 2004 in the 14th attempt to restore central rule
to Somalia since the 1991 ousting of a military dictator, the
government's authority has been challenged by the rise of an
Islamist movement that took Mogadishu and other towns in June.

Born out of sharia courts created from the mid-1990s to
restore some order to Mogadishu during a period of anarchy and
violence, the Islamists defeated U.S.-backed warlords in
Mogadishu and have since expanded to take other towns.

With Ethiopian troops now said to be in Somalia to support
the government, and Eritrea believed by many to be arming the
Islamists, many Somalis are bracing for full-scale conflict.

Officials would not give details of the two men arrested on
suspicion of involvement in the shooting.

Other sources in Baidoa, however, said one was a young
Muslim fundamentalist based at the same mosque.

ISLAMISTS DENY INVOLVEMENT

Islamist rulers in Mogadishu denied involvement, saying
Ethiopia was behind the killing to destabilise its neighbor.

Ethiopia did not immediately respond to the accusation but
charged Eritrea actively supported radical Islamists in
Somalia.

"If there is anyone who is reluctant to support peace and
stability in Somalia, it is only the Eritrean government that
is trying to disturb the region by allying itself with
extremist elements," a government statement said.

Shocked diplomats and analysts said the shooting could have
been by an Islamist militant or linked to internal divisions
within the government. A no confidence motion on Prime Minister
Ali Mohamed Gedi is due to be debated in parliament on
Saturday.

Amid the tensions, a curfew was imposed in Baidoa
overnight.

In what government sources said was an effort to draw the
Islamists into peace talks, 18 ministers and other top
officials quit the government on Thursday. Analysts said
power-sharing with the Islamists may be the only way to secure
peace.

In Mogadishu, meanwhile, another mysterious plane landed on
Friday, fuelling suspicions the Islamists were receiving weapon
deliveries. Their militia blocked roads near the airport as
unidentified cargo was unloaded on to waiting trucks.

On Wednesday, a cargo plane delivered goods an Islamist
aide said were sewing machines. But the government pointed the
finger at Eritrea, which it said was secretly arming the
Islamists.

(Additional reporting by Mohamed Ali Bile in Mogadishu, and
Marie-Louise Gumuchian and Andrew Cawthorne in Nairobi)